Abstract: In order to improve the gas lock,unreasonable injection parameters and other problems in the foam flooding of Lukeqin heavy oil reservoir,the deoxidized air foam flooding injection parameters were optimized by laboratory physical simulation experiment.Research indicates that a maximum recovery degree increment and a significant water cut increase can be realized by immediately carrying out deoxidized air foam flooding after water breakthrough.Alternate gas-liquid injection pattern is recommended rather than gas-liquid coinjection pattern to avoid gas-liquid separation and corrosion in wellbore.A comparable displacement performance to gas-liquid coinjection can be obtained when the single injection volumes of deoxidized air and foam liquid are 0.1 time pore volume.The optimal parameters according to the laboratory test include foam flooding implementation when the water cut is 70%,alternate liquid-gas injection,0.1 time PV injection in a single treatment.After field parameter adjustment,the daily oil increment of test zone is 42 t/d,the water cut is reduced by 28 percentage points,the cumulative oil increment is 1.4×10⁴t,and the water production is reduced by 2.65×10⁴m³.Field test shows a favorable feasibility for the deoxidized air foam flooding program,which could provide certain technical reference for the large-scale development of Lukeqin heavy oil reservoir.

Key words: heavy oil, foam flooding, parameter optimization, conversion timing, injection volume, injection rate